Known compounds useful as organic electronic materials, such as organic semi-conductors, include tetracyanoanthraquinodimethane and derivatives thereof as disclosed, e.g., in Japanese Patent Application (OPI) Nos. 149259/82 and 55450/83, etc.
The tetracyanoanthraquinodimethane compounds have a basic skeleton represented by the following formula ##STR2## with various substituents being bonded thereto.
These tetracyanoanthraquinodimethane compounds are synthesized from the corresponding anthraquinone compounds and are useful as organic electronic materials, such as organic semi-conductors, organic photographic materials, organic conductors, thermistors, and the like.
The inventors previously succeeded to isolate a charge transfer complex composed of the above-described tetracyanoquinodimethane compound and an electron donating compound at room temperature as a pure solid and found that the resulting charge transfer complex is more useful as an organic electronic material than the tetracyanoquinodimethane compounds per se. They also found that compounds derived from the tetracyanoanthraquinodimethane compounds by displacing at least one of the two benzene condensed rings thereof with other heterocyclic ring and modifying the two dicyanomethylene groups thereof with various groups are also useful as organic electronic materials well, as disclosed in Japanese Patent Application (OPI) Nos. 33157/87 and 32465/87 (the term "OPI" means an unexamined and published patent application).